The System.Data.OleDb namespace is the OLE DB .NET Data Provider.
A .NET data provider describes a collection of classes used to manage connections between an ASP.NET Web application and a data store, such as a relational database or a hierarchical XML file.
This namespace includes the core OleDb classes for accessing and manipulating any OLE DB-compliant data source, and essentially consists of the OleDbConnection, the OleDbCommand, the OleDbdataReader, and the OleDbDataAdapter classes.